Drilling implement



Dec.l14, 1937.

H. C. JOHA DRILLING IMP Filed May 4,

Rigi. E F295 NSEN LEMENT @Piggy 75 /llllllI-l'l/ 3 Patented Dee'. 14, 1937- iiiiialtr OFFICE 2,102,231; paname IMPLEMENT Harry C. Johansen; Michigan City, Ind., assignor to Sullivan Machinery Company, a corporation of Massachusetts v Application May 4, 1934,' serial No. '123,919

4 Claims.

This invention relates to drilling 'implements and more particularly to improvements in a drilling implement of the type )adapted to use with rotary 'drilling apparatus.

An object of this invention is t provide an improved drilling implement. Another object is to provide an improved drilling implement adapted to use with a, rotary drilling apparatus. A further object is to provide an improved drilling 104 implement of the so-called chatter" Ibit type having improved means for imparting a chattering or vibrating action to the cutting edges during the drilling operation thereby to improve the drilling action ofthe drilling implement. Yet another object is to provide an improved torsion spring type "chatter bit having associated therewith improved rotation limiting means between relatively rotatable parts of the bit'whe're- 'by when the bit sticks breakage of the torsion spring is prevented.` 'I'hese and other objects will, however, Yhereinafter more fully appear.

. In the accompanying drawing there is shown for purposes of illustration one form which the invention may assume in practice.

Fig. 1 is a sectionalview through a drill rotation and feeding mechanism-with which the illustrative embodiment of the improved drilling implement is associated. y v

Fig. 2 is a view partially in longitudi al section and partially in elevation'throu lustrative form of the improved drillingimplement. I

Fig.` 3 is a cross sectional view taken on line 3-3 of Fig. 2.

Figml is a side elevational view of the drill bit.-

Fig. 5 is an end view ofj the cutterv bit. A In. thisillustrative embodiment of the inven- -tion the improved drilling implement generally designated I is associated with a strip borer drill having feeding and rotation mechanism, although it will be evident that the improved' drilling implement may beused with rotaryvdrilli'ng apparatus of various other types.

The drill rotation and feeding mechanism shown comprises a rotation member 2 journalled within the drill head frame 3. The rotation member 2 isprovided with an axial drive opening l of polygonal cross section through which is slidable an axially movable and rotatable drive vrod 5 likewise of polygonal cross section Afor loose- Y ly fitting the polygonal drive opening in the rotation member. This drive rod carries a chuck 6 of any suitable `design for connecting lthe feed the ilastem 1. extending axially through'the drive rod,.

are rotated by lthe rotation member. they may be fed axially relative thereto by the feed piston. Liquid under pressure may be supplied to the feed cylinders through any suitable connections and the feeding pressure may be regulated -by any suitable control means.

The drilling implement I is connected-to the feed stem 'I and generally comprises a drill bit` I2 connected to the stem through a chattering or vibration producing connection I3 so that when the bit is rotated by the drive rod 5 the cutting portions thereof have imparted 'thereto a chatteringj/or vibrativechipping action. In this instance the feed stem 'I is threadedly connected at I 4 to abushing`|5 in turn threadedly connected at I6 to a tubular outer casing or spring housing I'I. Secured asv by welding or otherwise to the outer end of this tubular casing IIas at I8 is a drive bushing I9 having an axial bore 2U. In accordance with this invention', arranged within the tubular casing I'I is the improved. bit chattering or vibrating means comprising a coiled torsion spring 2| securedat its upper end as by welding or otherwise to a cylindrical portion 22 of an upper spring end plate 23. This member 23 is connected, as'by clutch y teeth 24, vto the .lower end of the bushing I5. 'I'he lower end of this spring is similarly secured "to a cylindrical portion 25 of, a lower spring end plate 26 in turn similarly connected as by clutchy teeth 21 to the head 28 of a rod-likedrive plug 29. 'This drive plugA is guided /in the tubular housing for axial'and rotative movements relative thereto and extends outwardly through the bore 20 in the drive bushing I9-and is threadedly connected at 30 at its lowerend to a bit head 3|. 'Die body of the bit I2 is mounted in a transverse slot 32 in this bit head and is secured there# in by a holding bolt 33. The coiled torsion spring 2l is a very powerful spring and adapted to resist torsional strain in such almanner that when it yields it stores up a very powerfulforce which acts in a direction tof rotate the drive plug 29 forwardly through an arc'equal to that through which it has been twisted.`

Improved means is provided for limiting the rotative movement of' the drive bushing I9 with respect, to the drive plug 29 lso that when the drill bit I2 sticks or is unduly resisted, breakage of the coil chatter spring 2| is prevented, and herein comprises lateral lugs 34, 34 formed on the drive plug 29 and movable in arcuate slots 35, 35 in the drive bushing and engageable with lugs 36, 36 on the drive bushing. The slots 35 are longitudinally elongated so when the drive plug has axial movement relative to the drive plug I9, the lugs 34 may move longitudinally in the slots. It will thus be seen that when the drive plug 29 is held against rotative movement by the sticking of the drill bit I2 the torsion spring 2| will yield until they lugs 36 on the drive bushing I9 engage the lugs 34 on the drive plug 29, so upon further rotative movement of the drive bushing the drive between the parts is positive.

The body of the drill bit I2 is centrally slotted at 31 to provide relatively long blades 38 having cutting edges 39, and these blades are so formed as to have a certain amount of inherent resiliency so a's to cooperate with the torsion chatter spring 2I in the vibrating of the bit cutting edges. In other words, the cutting blades of this bit are so formed so that when the bit is rapidly rotated, and, due to their inherent flexibility and the substantial degree of vibration which is effected las a result of the feeding pressure to which the bit is subjected will undergo a chattering or vibrating eiect which cooperates with the torsion chatter spring in the vibrating oi' the bit cutting edges.

The operation of the improved drilling implement will be clearly apparent from the description given. During the drilling operation the drilling implement is rotated by the K rotation means and a relatively powerful feeding force is imparted to the drilling implement by the hydraulic feeding mechanism. As the drilling implement is rotated, the cutting edges 39 will cut away the rock with an action which, due to the presence of the torsion chatter spring 2l, will involve a phenomenon or characteristic noi:` found in a drill bit of the usual rotary type. 'Ihe presence of the torsion "chatter spring will npermit very brief lags in the rotative speed ofthe bit compared with the rotative speed of the drive rod, and the inherent resiliency in the cuttingblades will cooperate with the torsion spring to increase the duration of these lags. As soon, however, as a suilicient pressure or rotativevforce builds up to break away the rock which has been obstructing the rotative movement of the bit, the torsion spring will restore the bit with a shocking',

chattering action to substantially the same position it occupied with respect to the drive rod prior to the occurrence oi' the lag. Thisloperation will be eiected many times a minute, and due to the friable or brittle nature of the rock, fory thedrillingfoi which this drilling implement is particularly adapted, will result in a much more rapid removal oi' the rock, the rock being notV merely planed oi! with a drilling action, but removed in chips of substantial size. 'I'he improvedl rotation limiting means associated with the "chattering means prevents the torsion spring-rrombeing broken or twisted oi! when the drill bit sticks. These and other/uses and advantages of the improved drilling implement will be clearly apparent to, those-skmedin the art.

While there isi in this application specifically described one form which the invention .may assume in practice, it will be understood that this form of the same is shown for purposes oi illustration and that the invention may be modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.

What I claim is new and desire to' secure by Letters-,Patent is:

1. In a rotary drilling implement, a rotary driving member, a relatively rotatable member carrying a drill bit, a. hollow longitudinal element disposed between said driving member and said bit carrying member, a torsion spring connecting said bit carrying member to said driving member and enclosed within said longitudinalv element, said bit carrying member rotatable relative to said longitudinal elem'ent upon yielding of said spring while remaining in the same relative longitudinal relation with said element, and abutment means associated with said longitudinal element and comprising an abutment on said bit carrying member and a cooperating abutment on said longitudinal element for limiting .yielding of said torsion spring, dueto relative rotation between said members, upon sticking of said drill bit.

`2. In a rotary drilling implement, a rotary driving member, a relatively rotatable connector element, a torsion spring connecting said connector element to said driving member, a sleeve surrounding said spring, said sleeve rigidly connected to said driving member, a drill bit secured to said connector elementnsaid drill bit and connector element being reciprocable rectilinearly and without rotation relative to said sleeve on compression and extension of said spring, and abutment meansk comprising an abutment on said connector element engageable with an abutment carried by said sleeve for limiting yielding of saidV spring, upon relative rotation between said connector element and sleeve, when the drill bit sticks. f

3. In an implement o1' the character described, a drive element, a drilling element, said elements being relatively rotatable, cylindrical guide portions fixed relativeto said elements and axially alined, a sleeve secured to one of said guide portions and slidably cooperating with the other, means ilxed relative to said last lmentioned portion for limiting movement ofthe latter into said sleeve, a torsion spring connecting sa elements, and abutment means! comprising an abutment iixed as regards rotation relative to said drilling element and a cooperating abutment ilxed as regards rotation relative to said drive element for limiting relative rotation between said elements providing substantially the same limit irrespective of the degree oi longitudinal deformation of the spring.

4. In an implement oi' the character described, a rotary drive element, a drilling element, said elements being relatively rotatable. yielding means lconnecting said elements, and means comprising an abutment ilxed as regards rotation relative to said drilling element and a cooperating abutment iixed as regards rotation relative to said drive element for limiting yielding of said yieldable means, upon relative' rotation between said elements, providing substantially equal limits oi' yield irrespective of the axial'dei'ormations of said yielding means.

' HARRY C. JOHANSEN. 

